Lord Derby was the first British statesman to become prime minister three times. He remains the longest serving party leader in modern British politics, heading the Conservative party for twenty-two years from 1846 to 1868. He abolished slavery in the British Empire, established a national system of education in Ireland, was a prominent advocate for the 1832 Reform Act and, as prime minister, oversaw the introduction of the Second Reform Act in 1867. Yet no biography of Derby, based upon his papers and correspondence, has previously been published. Alone of all Britain's premiers, Derby has...